Why do some people live well into their 90s while others don’t? A new study suggests the answer might be hiding in the bloodstream. Researchers have found distinct differences in common blood markers among people who reach their 90s and even 100s compared to those who don’t.
The findings highlight the role of metabolic health in longevity. Here, we’ll look at what the study uncovered, how these blood differences relate to long life, and what it could mean for the rest of us. Let’s get to it.
The research on blood and longevity
The study analyzed health data from 44,000 people in Sweden who underwent medical assessments between the ages of 64 and 99. Researchers then tracked participants for up to 35 years using national registry data. Out of the group, 2.7 percent—about 1,224 people—lived to be 100. The majority of these centenarians, around 85 percent, were women.
The researchers discovered that lower levels of glucose, creatinine, and uric acid were strongly associated with those who reached 100. Glucose relates to blood sugar regulation, creatinine reflects kidney function, and uric acid is a waste product from the breakdown of certain foods. People with healthier levels of these markers in their blood were more likely to reach advanced ages.
What makes the study especially striking is that these biomarker differences were visible years—sometimes decades—before death. That suggests the trajectory toward longevity may begin long before old age, shaped by genetics, physiology, and possibly lifestyle.
What this means for longevity
The findings point to metabolic health as a key factor in long life. Lower glucose levels are tied to better insulin function, which may reduce risks of diabetes and cardiovascular disease. Lower creatinine hints at stronger kidney function, while lower uric acid levels may protect against gout and other metabolic complications. Together, these markers may help explain why some people stay healthier into their 90s and beyond.
Still, the study wasn’t designed to isolate lifestyle habits. While it makes sense that nutrition, alcohol use, and other factors affect blood chemistry, the researchers didn’t measure these directly. Genetics also play a role, and so does chance. Even so, the findings reinforce the idea that everyday health measures—like keeping blood sugar in check and supporting kidney health—may help extend not just lifespan but healthspan.
Centenarians are now the fastest-growing age group in the world, with their numbers roughly doubling every decade since the 1970s. Studies like this add to a growing body of research showing that longevity isn’t random, but influenced by measurable biological and environmental factors.
While no single blood test can guarantee a longer life, tracking markers like glucose, creatinine, and uric acid may give doctors and patients a clearer picture of long-term health risks. The research also suggests that paying attention to these levels earlier in life could be just as important as managing them in old age.
Living past 90 may depend on more than luck. Our blood can tell a story that shows how genes, lifestyle, and biology work together to shape who reaches those milestone birthdays.